1. Field of the Invention
The present disclosure relates to a method of forming a conductor pattern using an etching mask.
2. Description of the Related Art
Wiring in electronic devices such as semiconductor devices or display devices typically includes a conductor pattern formed by patterning of a conductor film by etching. As the technology develops, miniaturization of the conductor pattern is required.
Japanese Patent Application Laid-Open No. 2007-81383 discloses a dry etching technology where a lower layer hard mask film is etched using an upper layer hard mask as an etching mask, forming a lower layer hard mask. Then, a film to be etched is dry-etched using the upper layer hard mask and the lower layer hard mask as etching masks.
In the technology according to Japanese Patent Application Laid-Open No. 2007-81383, the upper layer hard mask and the lower layer hard mask are used as etching masks immediately after the start of etching of the film to be etched. The upper layer hard mask is eliminated in the course of etching, and the film to be etched is etched using only the lower layer hard mask as the etching mask immediately before the end of etching. It has been learned that if the mask is changed during the etching process, side-etching may be caused at the side of the film to be etched, or the side may be provided with a slope or irregularities. Such phenomena may cause variations in the width of the conductor pattern, possibly resulting in a decrease in wiring characteristics or reliability.
The present technology is aimed at decreasing conductor pattern width variations.